Relational Class onAfterWrite After Final Write

class RelationalTerm extends DataObject {

    private static $db = array(
        'Title' => 'Varchar(200)'
    );

    private static $has_one = array(
        'ParentRelationalTerm' => 'RelationalTerm'
    );

    private static $has_many = array(
        'ChildrenRelationalTerms' => 'RelationalTerm'
    );

    function onAfterWrite()
    {
        parent::onAfterWrite();
        ExternalServiceInterface::executeReconfiguration($this->ID);
    }
}